spacedog/src/lib.rs
2025-10-17 17:25:47 -07:00

162 lines
4.2 KiB
Rust

use std::{
sync::{Arc, RwLock},
thread,
};
#[derive(Debug, Default, Clone, Copy, PartialEq, PartialOrd)]
pub struct Point2d {
pub x: f64,
pub y: f64,
}
#[derive(Debug, Default, Clone, Copy)]
pub struct PVal {
point_index: usize,
val: f64,
}
impl PartialEq for PVal {
fn eq(&self, other: &Self) -> bool {
self.val == other.val
}
}
impl Eq for PVal {}
impl PartialOrd for PVal {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
Some(self.cmp(other))
}
}
impl Ord for PVal {
fn cmp(&self, other: &Self) -> std::cmp::Ordering {
self.val
.partial_cmp(&other.val)
.unwrap_or(std::cmp::Ordering::Equal)
}
}
impl PVal {
pub fn new(point: usize, val: f64) -> Self {
Self {
point_index: point,
val,
}
}
pub fn point_index(&self) -> usize {
self.point_index
}
pub fn val(&self) -> f64 {
self.val
}
}
#[derive(Debug, Default, Clone)]
pub struct Spindex2d {
pub xpoints: Arc<RwLock<Vec<usize>>>,
pub ypoints: Arc<RwLock<Vec<usize>>>,
pub xs: Arc<RwLock<Vec<PVal>>>,
pub ys: Arc<RwLock<Vec<PVal>>>,
}
impl Spindex2d {
pub fn new(points: &[Point2d]) -> Self {
let mut xpoints = Vec::with_capacity(points.len());
let mut xs = Vec::with_capacity(points.len());
let mut ypoints = Vec::with_capacity(points.len());
let mut ys = Vec::with_capacity(points.len());
thread::scope(|s| {
s.spawn(|| {
for (i, point) in points.iter().enumerate() {
let x = PVal::new(i, point.x);
xs.push(x);
xpoints.push(i);
}
});
s.spawn(|| {
for (i, point) in points.iter().enumerate() {
let y = PVal::new(i, point.y);
ys.push(y);
ypoints.push(i);
}
});
});
let index = Self {
xpoints: Arc::new(RwLock::new(xpoints)),
ypoints: Arc::new(RwLock::new(ypoints)),
xs: Arc::new(RwLock::new(xs)),
ys: Arc::new(RwLock::new(ys)),
};
index.sort();
index
}
/// This method assumes that the points have the same cardinality and order as the points used
/// when constructing this index. May panic if the updated points argument is longer than the
/// original points.
pub fn update(&self, points: &[Point2d]) {
thread::scope(|s| {
s.spawn(|| {
let mut xs = self.xs.write().unwrap();
let xpoints = self.xpoints.read().unwrap();
for (i, point) in points.iter().enumerate() {
let xi = xpoints[i];
let x = PVal::new(i, point.x);
xs[xi] = x;
}
});
s.spawn(|| {
let mut ys = self.ys.write().unwrap();
let ypoints = self.ypoints.read().unwrap();
for (i, point) in points.iter().enumerate() {
let yi = ypoints[i];
let y = PVal::new(i, point.y);
ys[yi] = y;
}
});
});
self.sort();
}
fn sort(&self) {
let xs = self.xs.clone();
let points = self.xpoints.clone();
let xhandle = thread::spawn(move || {
let mut xs = xs.write().unwrap();
xs.sort_unstable();
let mut points = points.write().unwrap();
for (i, x) in xs.iter().enumerate() {
let p = x.point_index;
points[p] = i;
}
});
let ys = self.ys.clone();
let points = self.ypoints.clone();
let yhandle = thread::spawn(move || {
let mut ys = ys.write().unwrap();
ys.sort_unstable();
let mut points = points.write().unwrap();
for (i, y) in ys.iter().enumerate() {
let p = y.point_index;
points[p] = i;
}
});
xhandle.join().unwrap();
yhandle.join().unwrap();
}
}